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To determine the Residence Time Distribution (RTD) of a continuously stirred tank reactor (CSTR) as a function of stirrer speed using tracer measurements. (ii) To compare the predicted conversion of a second order reaction in a CSTR using the segregation model, with experimentally measured values. Theory : Most continuous reactors are non-ideal, i.e. they do not conform to either the PFR or CSTR models of ideal flow through a reactor. In CSTR reactors there may be dead zones and imperfect mixing regions. In tubular reactors there could be axial dispersion along the reactor length or the flow is laminar. The non-ideality is reflected by the differences in the residence time distribution (RTD) curve of the reactor and that expected for an ideal reactor model. To obtain the residence time distribution curve a tracer is sent into the reactor inlet, usually as a step or pulse input, and the concentration of the tracer leaving the reactor is measured as a function of time. In this study a step input is employed and the tracer used is sodium chloride (salt). The concentration of tracer is measured by measuring the conductivity (Λ(t)) of the solution. With a step input the cumulative distribution F(t) versus time curve is first obtained where F(t) is defined as: o (t ) F(t ) Λ Λ= where Λo is the maximum or plateau conductivity. Then the residence time or age distribution E(t) is obtained via...